The OMG have made the trading service one of the basic CORBA services. A specification has been drawn up (OMG RPF5) but seems to have some problems in terms of scalability and complexity. This paper introduces an architecture called Contextual Clustering Using Service Properties (CCUSP) that deals with issues of scalability. It uses a contextual approach to clustering object service offers based on property commonalities. It also handles issues of scalability of trader federation. An ontological approach is to be used, however not covered in this paper. An implementation of the specialisation graph context model is detailed.